Cutter for sheet material



March 23 1926.

, J. R. GAMMETER CUTTER FOR SHEET MATERIAL Filed April 16, 1924 2 Sheets-Sheet 1 2 AZQJ EQM March 23,1926 1,577,621

J. RJGAMMETER CUTTER'FOR SHEET MATERIAL Filed April 16, 192 2 Sheets-Sheet 2 Patented Mar. 23, 1926. I

UNITED STATES 1,577,62i PATENT orrics.

J R. GAMMETER, 0F AKRON, OHIO, ASSIGNOR TO THE B. F. GOODRIGH COMPANY OF NEW YORK, N. 'Y., A CORPORATION NEW YORK.

CUTTER FOB, SHEET MATERIAL.

Application filed April 16, 1924. Serial No. 706,343.

To all whom it may concern:

Be it known that 1, JOHN R. GAMMETER,

improvement upon those of my copending applications Serial No. 474,320, filed June 2, 1921, and Serial No. 563,570, filed May 25, 1922.

Knives heretofore used with rotary cutters of the character described have been subject to frequent and annoying breakage,

'due in part to their relatively large section and stiffness which makes it diflicult to obtain uniform temper throughout their length. To a larger degree however, said breakage has been due to the fact that the knives, which are mounted upon a yieldmg support, have been rigidly anchored at their respective ends and the hardened platen roll, which presses the work against the knives, bears against said knives in a rolling action progressively from one end to the other and causes the knife to buckle as the point of contact approaches its rigid anchorage.

The chief object of my invention is to provide a rotary cutter with efiicient and durable cutting knives. A more specific object is to avoid buckling and consequent breakage of such knives.

Of the accompanying drawmgs:

Fig. 1 is an elevation of a rotary cutting drum and associated parts, embodying a preferred form of-myinvention, and the work therein,

Fig. 2 is a section on line 22 of Fig. 1.

Fig. 3 is an enlarged elevation of one of the knife-anchoring members and adjacent parts, partly broken away and secti ned.

Fig. 4 is a plan view of the parts shown in Fig. 3.

Fig. 5 is a section, on a large scale, on

- line 55 of Fig. 3.

Fig. 6 is a section, on a large scale, on line 6-43 of Fig. 4.

Referring to the drawings, 10 is a rotatable, cylindrical drum upon which are helically wound a plurality of thin, flexible metalknives 11, 11, and 12 is a hardened metal roll against which the knives 11 are adapted to cut a fabric strip 13 which constitutes the work, the latter passing partly around said roll to the cutting position. Guide rolls 14, 15 are positioned adjacent and parallel to the drum 10, over which passes 'a liner 16, so guided by said rolls as to pass partly around the drum, as shown, to hold against the drum the bias-cut strips of fabric, cut by the knives 11 and carry them from the drum in orderly relation. Suitable means, (not shown) are provided for driving the several rotary members, the drum 10 and hardened roll 12 being driven at the same peripheral speed.

The knife 11 consists of a thin strip of tempered metal such as spring steel, and is mountededge-wise in a slot in a metal support or holder 17, with a suiiiciently loose fit to permit relative longitudinal movement of the knife. The holder 17 preferably is square in cross-section, the slot thereing being diagonally disposed. The holder 1s seated in a V-groove formed in the outer surface of a rectangular strip of resilient rubber 18, the latter being seated in a helical groove 19 of corresponding shape formed in the surface of the drum 10, and constituting a yielding backing for the knife.

The backing strip 18 is laterally reinforced by 'a sinuously looped wire 20 imbedded and vulcanized within it, the sinuous form of the wire permitting the free bending of .the strip to conform it to the helical groove 19 of the drum. The backing strips 18 are retained in their respective slots 19, preferably under substantial compression, by plates 21, 21 screwed to the face of the drum 10 and overlapping to margins of said strips, the strips thus being adapted to offer sutlicient resistance to force the knives through the work, although sufi'iciently yielding to insure proper contact of all parts of the knives with the hardened roll 12.

The plates 21 also are adapted to prevent llO ance between said brackets and the platen roll 12, and to permit a substantially straight pull upon the knives and holders. The end of the holder 17 is mounted in a recess in an anchor bolt 23, being secured therein by a transverse pin 24, each anchor bolt extending through an aperture in its respective bracket 22 and adjustably secured by a nut 25 at the opposite side thereof.

The anchor bolt 23 is formed with a radial slot 26 extending into its holder-receiving recess, to accommodate the knife 11, which is bent angularly in its own plane to separate it from the holder 17 so that it may be separately anchored. The front end of the anchor bolt 23 is threaded-to receive a collar 27 which fitsclosely about the knife and its holder in front of the anchor-bolt, to prevent separation of the same beyond this point. The collar 27 has a radial slot 27, which, when aligned with the slot 26 of the anchor bolt permits the insertion or re moval of the knife 11 without removal of said collar from the anchor bolt.

The ends of the knives 11 are secured in the heads of respective anchor bolts 28, each of which extends through an obliquely disposed aperture in the anchor-bracket 22 above the anchor bolt 23. The head of the anchor bolt 28 is formed with a recess 28 open to its end face through a narrow slot 28", accommodating the knife and the end portion of the knife 11, within said recess,

is looped around a removable wedge 29 are anchored to the respective brackets 22 by nuts 30 threaded onto their outer ends, this being the end of the drum at which the knives 11 first come into contact with the roll 12 during the operation of the machine. At the other end of the drum the stem of each anchor bolt 28 is surrounded by a helical compression spring 31, interposed between abuttin retaining nuts 32, 32 on said. stem and t e adjacent face of the anchor bracket.

In the o eration of the rotary cutter, the successive ives 11 contact the hard roll 12 first attheir ends which are rigidly anchored, and. the rolling-contact pro esses toward their yieldingly anchored en s, the

drum being of such size and the knives being disposed at such angle thereon that the trailing end of said knife passes out of contactwith the platen roll before its leading end again contacts therewith. The knives 11 being slidable within their respective holders l7, buckling of the knife is avoided,

nearest the springs 31 maintaining tension upon the knives while the latter creep. longitudinally in their respective slots under the force of the platen roll, and said springs permit retraction of the knives after they. pass out of engagement with the platen roll.

My invention permits the use of a knifeof such thinness that when positioned edgewise it is sufliciently sharp to sever the work, so that sharpening of the knife is not required. Such knives are capable of more uniform tempering than those of larger cross-section, so that they may be made more durable, and expense is saved both because breakage is reduced and because the knives are inexpensive. The simple arrangement for mounting the knives results in a saving of time and labor in replacing one that has broken.

My invention may be modified within its scope and I do not limit my claims wholly to the exact construction shown.

I claim:

-1. In a cutter for sheet material, the com bination of a knife-holding member formed with a knife-receiving slot of substantially uniform width throughoutits knife receiving region, an upstanding, strip-metal knife of substantially uniform thickness slidably mounted in said slot, means for so holding the knife in the slot as to permit its elongation and contraction therein, and means bination of a knife-holding member formed with a knife-receiving slot having substantially uniform width throughout its knifereceiving region,-an upstanding strip-metal knife mounted in said slot, and means for forcing the work against said knife in a progressive cutting action.

4. In a cutter for sheet material, the combination of a knife holding member, a flexible knife mounted and laterally supported therein, means for rigidly anchoring one end of said knife, means for yieldingly anchoring the other end thereof, and a roll adapted to press the work against said knife progressively from its rigidly anchored end toward its yieldingly anchored end.

5. In a cutter for sheet material, the combination of a knife-holding member formed with a knife-receiving slot having substantially uniform width throu hout its knifereceiving region, an upstan ing, strip-metal knife slidably mounted in said slot, means for rigidly anchoring one end of said knife,

- upon said drum, means on said drum forlat erally supporting said knife, yielding means for holding said knife under longitudinal means for retaining'the rest of the knife in said slot while permitting'it to elongate and bination of a knife-holding'drum, an up 7 knife.

contract therein, and means for forcing the Work against knife in a cutting action progresslng'from the rigidly anchored end to.-

ward the yieldingly anchored end of said 6. In a cutter for sheet material, the comstanding, "strip-metal knife helically wound tension, and means for forcing the work against said knife in a progressivecutting action. c v

7. In a cutter, for sheet material, the combination of a knife-holding drum, a flexible knife helically wound thereon, yielding means for holding said knife under longitudinal tension, and means forforcing the work against said knife in a progressive cutting action;

8 In a-cutter for disposed knife-holding means on said drum formed with'a knife-receiving slot having substantially uniform Width through its sheet material, the combination of a knife-holding drum, helically-' knife-receiving portion, an upstanding, strip-metal knife mounted in said slot, and means for 'for'cing the work against said knife. in a progressive cutting action.

9. In a cutter for sheet material, the comsupported thereon, means for rigidly anc oring bination of a knife-holding drum, a flexible I "k nife helically mounted andlaterall one end of said knife, means for yieldingly v standing, strip-metal knife helically Wound upon said drum, means on said drum for laterally supporting said knife, means for rigidly anchoring one end of said knife,- yield ing means for anchoring the other end of said knife, and means for forcing the Work against saidknife in a cutting action progressing from its rigidly anchored end to- Ward its yieldingly anchored end.

In witness whereof I have hereunto set 12th day ofApril, 1924.

my hand this n OHN R. GAMMETER. 

